The present invention relates basically to wind energy conversion devices and more particularly to such devices that operate on a vertical rotational axis.
It is presently becoming more important to provide means for creating electrical energy without reducing the world's supply of fossil fuel. Various successful attempts have been made to convert energy of natural phenomena to electricity as evidenced by hydroelectric dams, geothermic steam converters, and solar energy conversion devices. Although serviceable on a large scale, these apparatus cannot be solely relied upon to supply sufficient electrical energy for presently increasing needs.
Wind energy, although it has been long utilized for other purposes, is seldom used to generate electrical power, primarily because wind is unpredictable and very difficult to control. One particular problem is to design a wind energy conversion device that will withstand sudden high velocity bursts of wind and that will further operate efficiently in relatively low wind velocity. This problem has been considered in U.S. Pat. No. 704,507 to Bruneau. Bruneau discloses a windmill that operates on a horizontal axis and utilizes flexible fabric sails that are operatively attached to a counter weight mechanism. During gusts of wind, the sails automatically adjusts correspondingly to raise or lower the counterweights and thereby prevent damage to the windmill or sails attached thereto.
U.S. Pat. No. 1,766,765 to Savonius discloses a fixed vane rotor that includes vanes fixed to a centrifugal clutch arrangement in a hollow cylindrical housing to produce optimum efficiency in converting wind energy to drive an electrical generator. U.S. Pat. No. 1,046,026 shows a series of concentric tracks having sail driven carriages thereon for turning a center shaft. Each sail is loosely tethered to its respective carriage, allowing it to shift about its mast in response to wind force.
U.S. Pat. No. 3,793,530 to Carter discloses a wind turbine generator using a louvered drum that is rotatably mounted to a shaft for free rotation about a vertical axis. The plurality of louvers are connected by linkages that operate to expose a large surface area on one side of the rotor, and to turn the louvers on the opposite side of the rotor to present a relatively smaller surface area to the wind direction. A similar apparatus is disclosed in U.S. Pat. No. 3,743,848 to Strickland.
U.S. Pat. No. 2,633,921 to Monney also discloses a windmill that operates similar to the Bruneau windmill in that it is supplied with a force dampening spring to prevent damage of the windmill during high velocity winds.
Although the above cited apparatus appear serviceable, most are rather inefficient or utilize much of the wind energy for controlling the apparatus themselves, rather than for generating electric current.
It is a primary object of the present invention to provide a wind energy conversion apparatus that will operate more efficiently to convert wind force to shaft torque.
An additional object is to provide such an apparatus that will function both in high velocity winds and in situations where there is little wind current.
A yet further object of my invention is to provide such an apparatus that includes safety features to prevent damage from being done to the elements thereof during gusts or excessively high velocity wind.
These and other objects and advantages will become apparent upon reading the following disclosure which, taken with the accompanying drawings, describes a preferred form of the present invention.